Battery Operated 6.5" LED Fluorescent Glow Sticks

You can never have too many glow sticks at Burning Man. No, they're not for waving back and forth at a DJ while you're on the dance floor. (Though, I did witness "kids" doing this when Oakenfold and Tiesto spun at the 2005 Burning Man. My head was shaking. It's not a concert, folks!)
Anyhow, I clip these to my backpack, tape them on the spokes of my bike (which creates fancy spinning lights when you are riding), tie them to my tent stakes so people don't trip, and yes, even use them as ambient lighting if the night calls for it. They're very handy!
For a VERY funny video of how great glow sticks are, check out this video I've referenced. Seriously, it's excellent!